Is it o.k to be obssessed with things?

I know I've got an obssessive personality anyway, but I'll find myself thinking about things all the time (like lingering in the back of my mind), like anime series, favourite pairings in anime or whatever. Thinking about these things makes me happy (but usually all the time) and when I get the opportunity to talk about a mutual interest with someone I'm scared I'll sound too obsessed. Is this normal? I really don't want to be a freak :S